Steam-boiler



UNITED STATES PATENT EEICE.

JOHN A. CALDIVELL, OF BAY RIDGE, NEW YORK.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 439,105, dated October 28, 1890.

Application filed July 3, 1890. Serial No. 357,693. (No model.)

To all whom it may concern;

Be it known that I, JOHN A. CALDWELL, a Subject of the Queen of Great Britain, and a resident of Bay Ridge, in the county of Kings and State of New York, have invented a new and useful Improvement in Steam-Boilers, of which the following is a specification.

My invention appertains to that class of boilers called sectional or water-tube, in which the water is within the tubes and the dame without, the tubes arranged staggering, in nests, preferably, of four tubes to each header, a series of such boxes or headers being interconnected to form the water-legs of the boiler.

My invention comprises an improved method of shaping or constructing said headers as contain four tubes, so as to admit of connecting one to the other of the series by means of two nipples in the top and bottom portions of each header, instead of with one nipple, as heretofore, and at the same time retain the staggered position of the tubes', as will be hereinafter described, and specically pointed out in my claims, reference being had to the accompanying drawings, in which- Figure l represents a side elevation of a water-tube boiler constructed according to my present invention. H is the steam and water drum, and Q T the water-legs, of the boiler, interconnected by the nipples d and secured by saddles E to drum H. At the lower end of the rear water-legs is the usual mud-drum F. In such boilers the circulation of the water is along the inclined tubes, from the back to the front ot' the boiler, up the water-legs or headers to the steam and water drum H, thence along the drum to the back. end of the boiler,

down the back connection to the tubes P, to the back water-legs T, and along the inclined tubes, as before. It is very desirable that this circulation be as free and unirnpeded as possible, as on this depends the steaming qualities of the boiler. Y

Fig. 2 is a front view of four headers in section, the line of division being through the connecting-nipples ce d a, a, constructed so as to admit of the use of two nipples in connecting one to the other and leave a proper space c c between the nipples sufficiently strong to withstand the strain of expanding said nipples into place and also of retaining the usual staggering position to the tubes, as shown. It is a very desirable thing to have two nipples here instead of one, as heretofore, because where the headers are placed one on top of the other, four high, as in practice, then Where there is only one nipple connecting each header to its fellow it follows that the water of sixteen tubes as it circulates to the drum above is all required to pass through the nipple d d, fastened in the saddle E, whereas when two nipples are used, as in my construction, and the proportion thus changed from one to eight, the rapidity of the circulation is just doubled, thus making the boiler that much more efficient in steaming qualities at cornparatively little additional cost.

In all headers of this class hitherto in use the dividing or determining line of their configuration has been through a point just midway between the tubes, with the result that the headers overlap each other so far as to preclude the idea of using two nipples appreaching the diameter of the tubes of the boiler. This difhculty I overcome by constructing the headers so that the dividing-line is not made coincident with a point midway between the tubes of the boiler, but by constructing the longer and opposite points ofthe rhomboidal-shaped lheaders nearer together and the shorter and opposite points or corners farther-apart, resulting in aconiiguration more nearly approaching a true quadrangle than that due to the exact position of the tubes. Thus the amount of overlap is reduced to a minimum and the adjoining surfaces of the headers are more nearly coincident to each other and ample room provided for the use of two nipples of pratically the same diameter as the tubes of the boiler.

It is true that one large nipple is just as good as two smaller ones, and that the old lines of construction admit of using one large nipple or two smaller in diameter than the tubes of the boiler; but since the tubes of the boiler are usually four inches in diameter, or 12.56 inches area, it would follow that the area my construction provides for the water of circulation through the water-legs is 25.12 inches, or just double', and a single nipple to be of equal area would require to be ve and three-fourths inches Vin diameter, and, the nearest commercial size to thisbeing'six inches IOO diameter, it follows that that size would require to be used so as to equal the two nipples used inmy construction. To use this sized nipple would not only call for each header being two inches wider, and thus using a great deal more material in construction, but also necessitate sending out with each boiler a Very odd and costly size of tube-expander, adding to the cost of the boiler to that extent. Again, if the attempt were made to use two small nipples with the old construction, these nipples would require to be not more than three inches in diameter when the tubes are four inches, so as to leave a practicable size of partition between them. Theuse of two such small nipples would defeat the whole 0bject aimed at bybeing almost no more effective than a single nipple of fourinches diameter, (the size of the tubes.) I mention these cases to show that I do not claim them, and also to show the value of the construction that I do claim. Indeed, the fact that no headers have ever appeared connected with one nipple of larger diameter than the diameter of the tubes of the boiler, nor with two nipples of smaller diameter than the tubes of theboiler, shows that neither plan has been considered practicable.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-` 1. The method hereinbefore described of fabricating the water-legs of a sectional steamboiler, in which the tubes are set staggering and the headers or sections contain four tubes fastened therein, so as to admit of connecting ples, substantially as and for the purpose set forth.

3. In a boiler-header, the combination of four tubes fastened thereto in a staggered position, with two nipples inserted and fastened in the top and in the bottom portions for the purpose of joining it to its fellows above and below it, so as to form a portion of the waterlegs of a sectional steam-boiler, substantially as shown.

4. In a sectional steam-boiler header, the combination of four tubes fastened thereto in a staggered position, with two nipples inserted and fastened in the top and bottom portions, said nipples being of practically the same diameter as the said tubes, substantially as and for the purpose set forth.

In witness whereof I have hereunto subscribed my name in the presence of two subscribing witnesses.

JOHN A. CALDXVELL.

Witnesses:

ROBERT HUfrcHINsoN, S. P. HUToHINsoN. 

